Electric welding device



April 13 1926. 7 1,580,401

J. B. BORGADT -ELECTRIC WELDING DEVICE 5 Sheets-Sheet 1 Filed Oct. 9,1924 A ah April 13,1926; 1,580,401

- J. B. BORGADT ELECTRIC WELDING DEVICE Filed Oct. 9, 1924 3Sheets-Sheet 2 C 0111 0c utoz v Jakwlifioryadi April 13 1926.

J. B. BORGADT ELECTRIC WELDING DEVICE 9, 1924 5 Sheets-Sheet 3 FiledOct.

n uc nfoz John/5i Borgadt Patented Apr. 13, 1926.

J'OHII' B. IBORGADT, OF CLEVELAND, OIBIIO.

ELECTRIC WELDING nnvrcn.

Application fi1ed October 9, 1924. Serial No. 742,660.

To all whom it may concern.-

l 3e 1t known that, I, JoHN B, BonoAn'r, a citizen of the United States,residing at I Cleveland, in the county of Cuyahoga and State of Ohio,have invented certain new and useful Improvements in Electric WeldingDevices, of which the following is a,

specification.

The resent invention relates to an electric resistance welder and hasfor its object 1 to provide a device of this character which embodiesnovel features of construction,- whereby the electric current which isutilized for heating the material'to the welding temperature can becaused to pass through the material being welded withoutarcing andwithout any appreciable loss of current due to poor contacts.

Further objects of the inventionare to provide .an electric resistanceWelder in Wl'llCll the electrical contact with the material being weldedis obtained through a series of contact shoes which engage the materialover an appreciable area and which snap quickly into and out ofengagement with the material sothat a perfect electrical contact isalways obtained and arcing is avoided. p p The foregoing result isaccomplished by using an electrode wheel or roller which is provided atits periphery witlra series of contact shoes arranged to successivelyengage the material as the wheel revolves, said shoes being movable andmounted to have a quick or snap action into and out of operativeposition.

One particular embodiment of the invention will be shown and describedin detail for illustrative purposes, although it will be understood thatmany modifications and changes can be made in the details ofconstruction without departing from the spirit of .the invention. I

For a full understanding of the invention, reference is to be had tothe-f0llowing description and accompanying drawings, in which r J Figure1 is a front elevation of an electricresistance welder which isconstructed in accordance with .the invention, one of the electroderollers being shownin section in order to illustrate more clearly thedetails of construction'.. t

Figure 2 is a side elevation of one of the electrode Wheels, 9. portionthereof being broken awayand shown in section.

Figure3 is a plan view of the inner face of one fof the electrodewheels, the bearing member being shown in section.

Figure 4 is an enlarged detail perspective view of one of the contactshoes.

Figure 5 is a similar view of one of the brushes.

' Corresponding and to in the following cated on all of the views of bylike reference characters.

like parts are referred description and indi- Referring to the drawingswhich illus-' trate one of many possible embodiments of the invention,the. reference characters A designate a pair of electrode carryingwheels which are supported by the bearings B and arranged in cooperativerelation to the work. For illustrative purposes the wheels are shown asarranged to act upon a piece of pipe or tubing C for the purpose ofwelding a seam D atone side thereof. The tube is intended to be advancedin the usual manner and the wheels A cause a suitable electric currentto be passed across the seam D of the tube as it is advanced, wherebythe opposite sides of the seam are the drawings heated to the 'propertemperature to be' welded together. Suitable guides E are shown forsupporting the tube 6- and an conventional means may be utilized for avancing the tube through the welding device. The electric. current whichis used may besuitably stepped down by means of a transformer so that ithas the necessary high amperage and low voltage to-heat the material ofthe tube to the welding temperature as it passes through the tube. Theforegoing is the-usual process utilized for electric seam Welding by theresistance method,

although the usual apparatus. employs electrode wheels, each of whichhas a rolling contact with the tube and only contacts with the same at apoint. Owing to the fact that there is only a single point of pittingand each of the electrode carrying wheels is.

formed of a pair of spaced side lates 1 and 2, said side plates beingsepara 1e and the plate 1 being detachably secured by late 2. The hub isjournaled in one'hf the earings B, said bearing being divided and thehalves thereof being connected by fastening'members such as the screws8. The

bearing rotatably supports the electrode carrying wheel and holdsthewheel in proper position during the operation of the weldmg device.

The peripheral portions of the side plates 1 and 2 extend beyond thecentral portion of the wheel and form spaced side flanges between whichthe electrodes 9 are mounted. The electrodes are arranged in acontinuous series extending around the periphery of the wheel and thesides thereof have a sliding engagement with the inner faces of thesideplates 1 and 2. The electrodes are radially disposed with respect to thewheel A, and the adjacent edges thereof taper rearwardly so that theinner ends of the electrodes are sufliciently spaced from each other toadmit of the individual electrodes having an independent sidewiserocking movement.

The inner ends of the electrodes bear against a cushioning element 10which may be formed by an annular rubber ring surrounding the bodyportion 4 of the wheel. In the preferred construction there are twoseries of the electrodes 9 extending around each electrode carryingwheehand the electrodes 9 of each sei'ies are arranged in a staggered reation with reference to the electrodes of the other series. This is anarrangement which permits the work ng face of at least one of theelectrodes to be in full contact with the work at all times. The outerends or contact portions 9 of the elec trodes are preferably detachableand may be held in position in any suitable manner as by means of thescrews or fastening mem bers 11. If desired an interlochin joint may beformed between the electro es and the detachable contact ends 9 thereof,and, as shown on the drawings, the outer end of the body portion 9 ofeach electrode is formed with a central tongue 12 which engages acorresponding recess in the detachable face portion of the electrode,thereby insuring an accurate fitting of the detachable face or contactportion 9 to the body ortion 9. Theremovable outer ends or s cos 9 haveface portions 9" which are shaped to fit accurately against the surfaceof the ar ticular thing being welded. A good e ectrical co'ntact is thusobtained over the 381m" 7 tireare'a of the face portion 9? or the shoema am so that the electrodes or shoes can have a limited in and outradial movement, and it is intended that the rubber ring or cushioningelement 10 shall act to hold the contact shoes of the electrodes incontact with the work under a considerable pressure so that there willbe a good electrical connection between the cont-act shoes and thematerial being operated upon.

The contact shoes 9 are tapered outwardly, .and the outwardly andinwardly converging edge portions of the electrode units meet at theshouders 15 which are at ders of adjacent electrode units being slightlyspaced from each other or having a rocking contact with each other sothat the'electrode units can have a limited sidewise rocking movementindependently of each other. It will thus be seen that each of theelectrode units is mounted so that it can have a limited in and outsliding movement and also a limited sidewise rocking movement, althoughthe cushioning ring 10 normally tends to hold the electrode unit at thewidest portions of the units, the shoulthe outer limit of its radialmovement and with the axis thereof in a radial position, so that it canrock sldewise in either direction under pressure. The body portion 9 ofeach of the electrode units may be formed of manganese bronze with goodresults, and the contact shoe 9 ma be formed of copper with goodresults. he contact shoes 9 are made removable so that the electrodescan be changed and adapted for work upon dif ferent articles by usingcontact shoes having face portions which are so shaped that they willfit accurately against the surface of the artic e being welded.

The bearings B within which the hollow hub portions 7 of the electrodecarrying wheels A are journaled are carried b supporting brackets F,said brackets aving their rear ends slidably mounted guide-"ways G, sothat they are movableto shift the electrode carrying. wheels toward andaway from the tube C or other article being welded. Suitable mehns,suchfas the screws H, may be utilized for acting upon' the bearingbrackets tq-cause the electrodes to be forced against the tube orarticle be ing welded with the required pressure. For

in the pressure of about 200 pounds per square inch will give goodresults, and the use of the rubber ring or cushioning element 10 causesthis pressure to be yieldably applied to the inner ends of the electrodeunits.

' 1 Fitted inthe outer end of the hollow hub portion 7 of,each of theelect-rodecarrying wheels is a plug element 16. Packing 17 suitablefastening members such as the screws 18.v The plug member is thussupported in position and maintained between the plug member and thehollow hub, although the hub is free to rotate in the necessary manner.I

Extending'through the plug are passages I 19 and 20, said passagescommunicating with the respective nipples 19 and 20 which project fromthe outer end of the plug. Lengths of hose 21 may be fitted upon thenipples to provide for a circulation of water through the passages ofthe plug. A 011'- culation pipe 22 is carried by the plug 16 and has oneend thereof fitted in the inlet passage 20 thereof. This pipe 22 extendsthrough the hollow central portion of the electrode carrying wheel andis provided with the lateral nozzles 23 which project into the outercirculation chambers 5 of the respective side plates 1 and 2. Anysuitable means may be provided for pumping or forcing the water throughthe inlet passage 19 of the plug and this water will be carried by thepipe 22 and nozzlesk23 to the water chambers in the side plates of thewheel. After circulating through these side plates the water can bepermitted to flow out through the outlet passage 20 and thiscirculationof water through the wheel will tend to keep the wheel coolat all times, thereby enabling the welding device to be usedcontinuously and avoiding the possibility that the device will betemporarily disabled by overheating.

The side plate 1 of-each of the electrode carrying wheels is formed witha stub shaft 24 upon which a sleeve 25 is'fitted, said sleeve being heldin position by a nut 26 and washers 27 The sleeve 25 is formed as partof a brush carrying plate 28 and the inner face of the said plate isformed with a series of recesses 29 within which the contact blocks orbrushes 30 are fitted. Yielding means such as springs or pieces ofrubber 31 are arranged back of each of the brushes 30, suitable pocketsbeing formed in the plate 28, and the brushes 30 are thus caused topress yieldably against the face of the electrode carrying Wheel. Aconsiderable number of these brushes is employed, each a water tightjoint is brush being comparatively large and the aggregate contact areaof all of the brushes is considerable, thereby providing fortransmission of the electric current to and from the electrode carryingwheels with a minimum loss and with a minimum amount ot heating. Inorder to insure a good electrical connection between the brushes 30 andthe plate 28, each of the brushes has a flexible wire or pigtail 32brazed or otherwise permanently attached thereto. are carried outwardlythrough openings 33 in the plate 28, and have their outer ends suitablysecured to the brush carrying plate 28 by means of fastening elements34. .This

arrangement makes it certain that each and every one of the individualbrushes 30 will at all times have a perfect electrical connection withthe respective brush carrying plate The brush carrying plates are formedwith upwardly conducting arms 35. which tele-,

scope within guideways 36 formed of conducting material. The engagementof the conductor arms 35 with the guideways 36 holds the respectivebrush carrying plates 28 against rotation, and the telescopingconnection between the conductor arms 35 and the guideways 36 enablesthe electrode carrying wheels to have the necessary limited 9 movementtoward and from the tube or other article being welded.

When the device is to be utilized for-seam welding on tubes or pipes,the two electrode carrying wheels A will be arranged in a substantiallyV- haped relation, as shown, by Fig. 1. the two wheels being spaced fromeach other and the contact shoes 9 at the peripheries thereof engagingthe tube or pipe C on opposite sides of the seam D. The bearing bracketswill be adjusted so that the contact shoes 9 will bear against the tubeor pipe C with the desired amount of pressure, it having been found, aspreviouslystated, that good results are obtainable with a pressure ofabout 300 pounds per square inch. As the pipe or tube C is slowlyadvanced, any suitable mechanism being utilized for this purpose, theelectrode carrying wheels will be revolved by a frictional engagementwith the tube. If the current is switched on there will be a flow ofelectricity through the wheels and across the seam D of the tube,whereby theedges of the seam will be. heated to the proper temperaturefor welding together. As the wheels revolve the contactshoes 9 of thevarious electrodes are brought successively into engagement with thetube C and the face portion of each contactshoe has such a contour that.it will fit snugly against the tube while it is in engagementtherewith. Owing to the fact that the entire face of the contact shoe isin engagement with the tube there is a considerable contact areabetwee'nthe tube and the elec- T he pigtailstrode carrying wheel, sothat the current can be transmitted to the tube without arcing and undueheating. It will also be remembered that each of the wheels A isprovided with two rows of the electrodes and that the electrodes of eachrow are in a staggered re lation with respect to the electrodes of theother row. Each of the electrodes will be forced inwardly against thepressure of the rubber ring or cushioning element 10 when thecontact'shoe thereof is brought into engagement with the tube C. and theaction of the cushioning element will hold the contact shoe forciblyagainst the tube with a heavy pressure. The sidewise rocking movement ofthe electrode will permit the contact shoe to remain in an intimateengagement with the tube for an interval of time, although this sidewiserocking movement of the electrode results in deforming the rubber ringor cushioning element 10 and producing l stresses therein. with theresult that after a certain period of movement with the contact Shoe inintimate engagement with the tube the contact shoe will he suddenlyrocked out of engagement with the tube. In other words, the-contactshoes have aquick movementor snap action as they are moved into and outof contact with the tube. and owing to the fact that the electrodes ofthe. two rows are in a staggered relation to each other there willalwavs be at least one of the contact shoes in full engagement with thetube. A broad contact area is thus maintained at all times between theelectrode carrying .wheels and the, tube. and this is an improvementover the conventional electrode wheel which hasonlv a rolling contactwith the tube or pipe with suclran insufficient contact area as to causearcing and burning or pitting of the work. The wheels are water cooledso that overheating is rendered impossible and the electric current istransmitted to and from the wheels through an adequate number of brusheswhich directly engage the wheels instead of through the hub andbearingiuthe usual manner, the latter bein objectionable for the reason that itresults in undue heating and quick wearing at the hub. The arrangementis such that a current having the necessary high amperage and lowvoltage can be conveyed to and from the article being welded with aminimum loss and without undue heating. The bearings serve only tosupport the wheels and no current is carried through them. \Vhile theparticular form of the invention which has been illustrated is intendedto be used for the purpose of seam welding a tube or pipefit will beunderstood that with simple and obvious changes the device'can bearranged for operating upon any desired articles to produce welded jointby electrical resistance welding.

Having thus described my invention what- I claim as new and desire tosecure by Letters Patent is,

1. In an electric resistance welder, a series of independent electrodes,a carrier upon which the electrodes are mounted for bringing theelectrodes successively into operaso that they are movable-relativethereto in the direction in which the carrier moves, the carrier servingto bring the movably mounted electrodes successively into engage mentwith the material being welded and yielding means acting upon theelectrodes to hold them in engagement with the work.

3. In an'electric resistance welder, a carrier, and a series ofelectrodes rockably mounted upon the carrier, the electrodes beingbrought successively into operative engagement with the material beingwelded by the movements of the'carrier and yielding means for moving theelectrodes into and out of operative position with a snap action.

4. In an electric resistance welder, a carrier, a series ofelectrodesmounted upon the carrier and having both a rocking movementrelative thereto and an in-and-out movement, said electrodes beingbrought successively into engagement with the material being welded bythe movements of the carrier, and yielding means acting upon theelectrodes for producing a snap action as they are engagcd'anddisengaged from the material being welded.

5. In an electric resistance welder, a carrier, a series of independentelectrodes mounted upon the carrier so that they are broughtsuccessively into operative position thereby, said electrodes eachhaving a contact face conforming to the shape of the material to beengaged thereby, so that it will engage the material over the entirearea of the face, and yielding means for producing a snap action of theelectrodes as they are successivelybrought into and out of opera tiveposition.

-6. In an electric resistance welder, a to tary carrier, a series ofelectrodes extending around the periphery of thecarrier, each of theelectrods being rockably mounted and having a contact face conforming tothe shape of the member to be engaged thereby and adapted to engage thesaid member over the entire area thereof, and yielding means acting uponthe electrodes for causing them to be moved into and out of operativeposition with a snap action as they are brought successively intooperative position by the rotation of the carrier.

7. In an electric resistance Welder, 0. ro-

tary carrier, a series of electrodes extending around the periphery ofthe carrier and each mounted to have an inand-ont move'- ment and arocking movement, each of the electrodes having a contact faceconforming to the contour of the member to be enga ed thereby andadapted to engage the mem er. over its entire face, and yielding meansact: ing upon the electrodes for causing them to engage action as theyare brought successively into operative position by the rotation of thecarrier.

8. In an electrlc resistance welder-,1;"fo 1 a plurality of series ofelec-' tary carrier, trodes extending around the periphery of thecarrier and having the independent electrodes thereof arranged instaggered relaside plates, and a electrodes to force them into tions andmounted for independentmove ment, and yielding means acting upon' theengagement are brought succes with the work as they therewith -by therosively into engagement tation of the carrier, the electrodes ofthedifferent series overlapping each other so that one pair ofelectrodes'is always n engagement with the work and a continuous anduniform seam is welded.

9. In an electric resistance welder, a rotary carrier, a pluralitytrodes extending around *the periphery of the carrier and arranged instaggered relations, said electrodes being rockably, mounted and formedwith contact faces, and yielding' means acting upon the electrodes formoving the contact faces into and out of engagement with the work with asnap ac; tion as they are brought successively into operative positionby the rotation of the carrier. t

10. In an electric resistance welder, an

electrode carrying wheel formed with spaced series of independentelectrodes loosely mounted between the side plates and arranged to bebrought successively into operative position as the wheel is rotated.

11. In an electric resistance welder, an

electrode carrying wheel formed with spaced.

side lates, a series of independent electrodes loose received betweenthe side plates, and

a cushioning element applied to the wheel and engaging the inner ends ofthe electrodes, said electrodes being arranged to be broughtsuccessively into operative position as the wheel is rotated. i 12. Inan electric resistance welder, an electrode carrying wheel formed withspaced side plates, a series -of independent electrodes loosely mountedbetween the side plates, and a rubber cushioning ring applied to thewheel and engaging the inner endsof the electrodes, said electrodesbeing arranged to be brought successively-into operative position as t ewheel is rotated.

and disengage the article with a snap of series of elec- V circulatinga. cooling 13. In an electric-resistance welder, an

electrode carrying wheel formed with spaced s de plates, a series ofindependent electrodes loosely received between the side plates so i asto slide radially and rock in the plane of the wheel, said electrodeshaving contact faces of appreciable ,area,'and cushioning and yieldingmeans acting on the inner ends of the electrodes whereby they snap intoand out of engagement w ththe member being welded as they are brought"operative position byfth 1 wheel. 14. In an electric resistance welder,an electrode carrying wheel formed with spaced side plates r two seriesof inde endent elece plates and trodes mounted between the si arrangedina staggered-relation, said electrodes having contact faces of anappreciable area and being mountedto slide radially and rock laterallyin the plane ofthe wheel, and a resilient ring applied to the wheel andengalng the inner ends of the electrodes where y the latter are causedto snap in and out of enga ement with the member being'welded. assuccessively into operative position by the rotation of the wheel.

15. In an electric resistance welder, an electrode carrying wheel formedwith spaced side plates, a series of independent electrodes looselyreceived within the side plates ey are brought so as to slide radially,said electrodes liaving'the edges thereof tapered inwardly and outwardlyso that each electrode can have a limited rocking movement in the planeof the wheel, the outerend of the electrode being formed with acontactf-ace of appre-' ciable area, and yielding means engaging theinner ends of the electrodes.

16. In an electric resistance welder, an electrode carrying wheel formedwith spaced side plates having recesses in the inner faces thereof, aseries of independent electrodes with the electrodes for 'holdlowelectrode carrying wheel, and means for circulating a cooling mediumthrough said electrode carrying wheel including a plurality of nozzlesfor directing the cooling medium toward the operative portion of theperiphery of the wheel.

19. In anelectric resistance welder, an

electrode Wheel including electrodes, h

low side plate extending along the sides of the electrodes and incontact therewith, and means for circulating a cooling medium 7 throughthe hollow side plate.

20; In an electric resistance welder, an electrode wheel, means upon oneside of the wheel for rotatably sup orting the same, the opposite sidethereof being flat and free from any supporting means, a brush carryingplate arranged on the said flat side of the wheel and a series ofbrushes mounted upon the plate and slidably engaging the said flat faceof the wheel over a considerable portion of the area thereof.

21. In an electric resistance welder, an electrode wheel, means on oneside of the wheel for rotatably supporting the same, the opposite sideof the-wheel being flat and free from supporting means, a brush carryingplate arranged on the said flat side of the wheel, means for obtaining apivotal connection between the brush carrying plate and the wheel, meansfor holding the brush carrying plate against rotation with the wheel,and a plurality of brushes mounted upon the plate and slidably, engagingthe flat face of the wheel over a considerable portion of the areathereof.

22. In an electric resistance welder, an electrode wheel h avin a flatface, a shaft projecting from the at face of the wheel, a sleeve looseon the shaft, a brush carrying plate mounted upon the sleeve andarranged opposite the flat face of the wheel, means for holding theplate against rotation, and a series of brushes mounted upon the plateand slidably engaging the flat face of the wheel over a considerableportion of the area thereof; 1

231 In an electric resistance welder, an electrode wheel, a shaft,projecting from one side thereof, a sleeve loose upon the shaft,

a brush carrying plate mounted upon the sleeve, a plurality of brushescarried by the brush carrying plate and slidably engaging a side of thewheel over a considerable por tion of the area thereof, and means forholding'the brush carrying plate against rotation with the wheel.

24. In an electric resistance welder, an electrode wheel, means on oneside of the 'Wheel for rot-atably supporting the same,

the wheel being entirely supported by the said means and free fromsupport on the opposite side, a stub shaft projecting from the saidopposite side of the wheel, a brush carrying plate provided with meansfor engaging the stub shaft, whereby it is support-

